JP-A-8-255981 discloses a technology in which an exposing process for a photo sensitive material with ultraviolet light is used to form microscopic via holes and wirings on a glass substrate. By forming a light shielding film of a metal such as Ti, Cr, Al, Ni, W, Mo, Ta and Cu on the glass substrate, multiple reflection of ultraviolet light between the upper and lower faces of the glass substrate is prevented at the time of the exposing process of the photo sensitive material. Further, by forming a light shielding film composed of one of the above metals having a thickness of more than 3 μm, the heat conductivity of the glass substrate is enhanced.
JP-A-9-321184 discloses a connection substrate for connecting a semiconductor chip having a high wiring density with a printed wire substrate having a low wiring density and a manufacturing method thereof. The connection substrate is composed of a photosensitive glass substrate and on the upper face thereof one layer of wiring is formed to which a bump for the chip is connected. Further, on the lower face of the substrate a plurality of bumps are formed, which are connected to electrodes on the printed wire substrate. The wirings on the upper face of the substrate and the bumps on the lower face are electrically connected through holes penetrating between the upper and lower faces of the substrate. These penetrating holes are formed through a photolithography and conductors are buried inside the penetrating holes through plating.
JP-A-2000-124358 discloses a high frequency integrated circuit mounting an active element in which an MIM type capacitor, a spiral inductor, a thin film resistor and metal wirings for connecting these are arranged on a silicon substrate and further, a flip chip is mounted thereon. Further, the claims thereof cover the use of a glass substrate, although the details thereof and the advantages thereof are not disclosed.
JP-A-10-284694 discloses a an electronic circuit on a poly crystal silicon substrate having a resistivity of more than 200 Ωcm.
As the wiring substrate for mounting electronic parts, one in which Cu wirings are formed on a resin substrate such as epoxy resin containing glass fibers (glass epoxy) or polyimide resin, or one in which W wirings are formed on a ceramics substrate such as AlN and SiC are broadly used.
However, the warp and size variation of wiring materials such as the resin and the ceramics are large in comparison with-those of silicon substrate which is used in the manufacture of the semiconductor integrated circuits, and the formation of microscopic wirings and through holes of the order of μm by using a photolithography is impossible. Therefore, it is difficult to mount the electronic parts in high density.
On the other hand, the suitability of a silicon substrate as the wiring substrate for mounting electronics parts, is low in comparison with a glass epoxy substrate, and thus its usage is limited. Further, since the single crystal silicon substrate is a semiconductor, the substrate operates to reduce the efficiency of the electronic parts such as a capacitor and inductor formed thereon. On the other hand, a poly crystal silicon substrate can prevent to some extent the efficiency reduction. However, the poly crystal silicon substrate is more expensive than the single crystal silicon and the general use property thereof as the wiring substrate for mounting electronic parts is low and the usage thereof is limited.
Since glass shows characteristics that the warp and the size variation are small in comparison with resin and ceramics and the cost thereof is inexpensive in comparison with silicon, it is considered that glass is a suitable substrate material for mounting electronic parts in high density. Further, the glass substrate is a desirable insulator, therefore the elements such as the inductors formed thereon show a high efficiency.
However, since the heat conductivity of the ordinal glass substrate as disclosed on JP-A-2000-124358 is low and is readily broken, cracks and damages are frequently caused due to difference of the thermal expansion coefficients between the glass substrate and other materials (Si). As a result, yield and reliability are reduced.
Further, in order to mount electronic parts on the glass substrate in high density as well as to use the glass substrate in a broad usage, it is necessary to lead out electrodes to be used as external connection terminals from the back face of the substrate (the opposite side from the mounting face of the electronic parts) as practiced in a wiring substrate composed of resin or ceramics.
In order to lead out the external connection terminals from the back face of the substrate, it is necessary to form through holes in the glass substrate in high accuracy; however, if a special photosensitive glass such as, for example, the glass disclosed in JP-A-9-321184 is used, the manufacturing cost of the substrate increases and its usage is limited as the substrate for mounting the electronic parts.
Further, as disclosed in JP-A-2000-124358, when all of the variety of the electronic parts such as the capacitor, inductor and resistor are arranged on the substrate, the size of the integrated electronic parts become comparatively large.
Further, in the above document, the respective constituting elements formed on the glass substrate are structured to be exposed at the end face of the substrate. When a large mechanical stress is applied at the interface regions of the respective layers constituting the semiconductor connection substrate, such as at the time of cutting out by dicing from a glass substrate larger than the electronic part, and when a large thermal stress is applied at the interfaces of the respective layers in connection with sudden temperature variation caused at the time of mounting the semiconductor connection substrate, these stresses are concentrated at the exposed end faces of the semiconductor connection substrate and the interface regions of the respective layers. As a result, the interface regions of the respective layers may be peeled off and the semiconductor connection substrate may be damaged.
Accordingly, these already known semiconductor connection substrates do not necessarily show a high reliability, and it is not necessarily easy to obtain a high manufacturing yield.
An object of the present invention is to provide a semiconductor connection substrate, which integrates a variety of electronic parts, such as a capacitor, inductor and resistor, wherein the electronic parts have a high performance and are present in a high density.